Project Summary Chronic stress for children growing up in poverty may lead to lasting effects on social, behavioral, and cognitive development. The difficulties of living in economic hardship has, indeed, been associated with deficits in cognitive and academic performance. The current study examines the link between poverty and executive functions (cognitive processes that facilitate learning, self-monitoring, and decision making) which are known to undergo rapid developmental change during the first years of life. Early neurological development will be examined as a mediator of this association examined from pregnancy to age 3. In addition to distal risk associated with living in poverty, we will investigate critical experiences within the proximal context (i.e., language exposure, caregiver behavior, child sleep hygiene) that may mediate the effect of this risk on child structural and functional brain development. Participants (n= 230) will be seen during the 28th week of pregnancy, and at 5 visits across the first 3 years of their child's life. Neuroimaging will be conducted at 2 weeks, 15 and 24 months (with an accompanying lab visit at 15 months). We will focus on developing white matter tracts that support cognitive processes of emerging executive functions: anterior cingulum (error monitoring); uncinate (joint attention); arcuate fasciculus (language processing) and individual differences in functional brain development, including resting state networks of salience, attention, executive control, and default-mode. At 6 and 24 months of age, an intensive home visit will include observational and objective measures of caregiver behavior, language exposure (via speech recorders) and sleep hygiene (via actigraphy for 7 days). Child cognitive development will be assessed at each assessment and an executive functioning battery will be administered at 36 months of age. This study will be the first to investigate the influence of poverty on emerging executive functioning at age 3 via effects on child neurological development over the first two years of life. In addition, findings will contribute critical information regarding whether specific measures of proximal experience (language exposure, caregiver behavior, child sleep hygiene) may mediate this risk.